definition of
sign

[1] #1 sign n. [mark] a perceptible indication of something not immediately apparent (as a visible clue that something has happened); "he showed signs of strain"; "they welcomed the signs of spring". wn

[2] #2 sign v. [subscribe] mark with one's signature; write one's name (on); "She signed the letter and sent it off"; "Please sign here". wn

[3] #3 sign v. [ratify] approve and express assent, responsibility, or obligation; "All parties ratified the peace treaty"; "Have you signed your contract yet?". wn

[4] #4 sign v. be engaged by a written agreement; "He signed to play the casino on Dec. 18"; "The soprano signed to sing the new opera". wn

[5] #5 sign n. a public display of a message; "he posted signs in all the shop windows". wn